I bought a used CASIO CTK-3400SK keyboard it makes a "click" sound when I release the keys, affecting the sound quality during recordings. I don't know how to solve this problem and
US 9V Power Adaptor for the Casio CTK-3400SK Keyboard by myVolts
Casio CTK-3400 Portable Keyboard Plus Stagg Stand | in Muswell Hill, London | Gumtree
Teclado Casio CTK 3400 é Bom? Vale a Pena? - Eu Escuto
DISC Casio CTK-3400 Portable Keyboard - Nearly New at Gear4music